1. Field of the Invention
This invention relates generally to color imaging technology and more particularly to a method for determining the optimal viewing angle of a display, such as a flat panel display. The same technique has applications for all display, input, or output technologies with limited viewing, output and/or sensing angle characteristics.
2. Description of the Prior Art
Various displays, such as flat panel displays, are based on technologies that are very different from CRT technology. For example, flat-panel LCDs for desktops use rod-shaped molecules that bend light to produce an image in contrast to CRTs that use electron guns that light up the phosphors on the viewing area of a glass tube. Flat panel LCDs do not have a CRT""s geometric, convergence or focus problems, and their clarity makes it easier to view higher resolutions at smaller screen sizes. Also, the latest flat panel displays are all digital, unlike CRT""s. This means that graphics cards with digital outputs do not have to convert the graphics information into analog form as they would with a typical monitor. Theoretically, this makes for more accurate color information and pixel placement.
Flat panel displays, however, suffer from viewing angle limitations. CRT""s radiate light roughly into a full hemisphere, while flat panel devices radiate light over a smaller solid angle that is highly directional. Consequently, moving the head or tilting the display changes contrast, brightness and colors of the screen in a dramatic way. For example, some conventional flat panel displays have less than 100-degree viewing angles, making it difficult to gather viewers around the screen or even for a viewer to shift his or her head without losing the image. Although some of the latest flat panel displays have 140-degree viewing angles or more on 15-inch panels or 160 or greater degree viewing angles on larger 18-inch displays, it is still desirable to determine the optimal viewing angle of the display. The optimal viewing angle ensures optimal contrast and brightness and consistent color rendering, which are especially important for applications using pictures or graphics, such as presentations, desktop publishing, browser use and so forth.
Conventional methods for determining the optimal viewing angle are generally rudimentary. For example, common methods include tilting the display until the image looks xe2x80x9cgoodxe2x80x9d to a user or viewing the display at an angle normal (i.e. perpendicular) to the display. Such methods may suffice for low level applications dealing mostly with text and saturated colors. However, with respect to pictures, the above limitations, resulting in lost contrast and brightness, become obvious. As the panel is tilted away from the optimum viewing angle, shadows, mid-tones or highlights fail to show contrast and detail, and colors are altered.
What is needed therefore is an apparatus and method for determining the optimal viewing angle of a display, such as a flat panel display, thus ensuring optimal contrast and brightness and consistent color rendering.
The present invention provides, in a first aspect, an apparatus for determining a predetermined viewing angle of a display including a computer program having logic for generating a test pattern including at least one indicator and a background, wherein appearance of the indicator is different from appearance of the background and difference in appearance between the indicator and the background at various viewing angles indicates whether the predetermined viewing angle has been determined.
In another aspect, the present invention provides a method for determining a predetermined viewing angle of display, including the step of generating a test pattern including at least one indicator and a background such that appearance of the indicator is different from appearance of the background and difference in appearance between the indicator and the background at various viewing angles indicates whether the predetermined viewing angle has been determined.
These and other features and advantages of this invention will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features of the invention, like numerals referring to like features throughout both the drawing figures and the written description.